1. Field of the Invention
The invention relates to a device for moving two doors on a side wall of a printing group in a rotary printing machine. Sleeve-type printing forms and/or rubber-blanket sleeves are exchangeable through openings that are covered and uncovered by the doors.
2. Description of the Related Art
A prior art device for moving two doors on a side wall of a printing group in a rotary printing machine is disclosed in EP 0 352 599 B1. In that reference, two doors of a printing group are movable between an open and a closed position. When closed, the two doors can receive the journals of two transfer cylinders and two form cylinders. The doors are moved by two motor-operable threaded spindles. When the doors are moved away from each other, openings in the side wall are uncovered through which the printing form and rubber blanket of the form and transfer cylinders may be exchanged.
Other prior art devices for opening doors on printing groups of rotary printing machines are disclosed in references DE 196 41 804 and DE 196 41 805. These references disclose pivotable doors of openings provided in a side wall of a printing group for exchanging the printing forms and the rubber blankets of the cylinders. To operate the doors, six hydraulic working cylinders are provided. A special component is required for preventing the doors from opening on their own if the hydraulic pressure drops. In addition, the doors require expensive bearings, which are also expensive to repair in the event of damage which may, for example, be caused by a winding malfunction.